Speaker spikes on concrete or wood floor best?

I would rather have a concrete floor if you have a choice between locations with either. Make sure that the covering for the concrete is sufficient to damp reflections. Due to water damage I just replaced the inherited from previous owner wall to wall carpet on my concrete floored listening room with vinyl flooring with 3 large wool area rugs and the improvement was well beyond expectations.

Concrete is the absolute best. But many do not have that option. I have wood floors over concrete and it works great.

I tried using the spikes that come with my Thiels, but prefer cork adhesive dots. Sounds better to me.

Great question and one that I never gave much thought to. My speaker/stands came with spike so I've always used them. First on wood and now on tile covering concrete.

May I rephrase the question to help the larger audience:

If you have concrete flooring should you use spikes or another material to anchor your speaker stands?

Likewise, if you have wood should you spike it or use a covering over it?